Abstract - Exposure Core A robust exposure assessment is key to the success of any environmental epidemiology or toxicology project. Exposures to organic chemicals and air pollutants have been implicated in adverse Nervous System, Respiratory Health, Immune System, and Endocrine and Metabolic Regulation outcomes, the theme areas of this Center. Determining exposure is complex as people are exposed to multiple compounds through multiple exposure pathways. Additionally, nutritional status has been shown to interact with chemical exposures so must also be assessed both as an influential exposure and as a cofactor in environmental health projects. Given the high degree of complexity for assessing exposure to compounds presently of high interest in epidemiological and toxicological studies, a multidisciplinary team is needed to design the exposure assessment, collect and analyze the data, and interpret the results. The overarching goal of the exposure core is to provide exposure study design and analysis expertise to improve the quality of studies requiring exposure assessment, and by extension, the quality of environmental health research conducted at UC Davis. This is accomplished through three mechanisms. First, a Design Team will hold Exposure Design Clinics that include PIs, exposure scientists, analytical chemists, and biostatisticians. PIs present the aims of their projects to the design team and the team works with the PIs to design appropriate and cost-effective exposure studies. Second, we provide investigators with resources to collect and analyze exposure samples by including laboratories with expertise in: target and non-target analysis of organic compounds in environmental and biological samples, time integrated modeled exposure concentrations, compositional analysis of collected air pollution and other environmental samples, including functional organic groups, and various elements and isotopes through XRF and ICPMS analysis, guidance for the design of animal inhalation toxicology studies using a range of air pollutants, and nutritional status through either questionnaires or biological markers. Third, we will provide investigators with assistance in interpreting their exposure assessment data by bringing the relevant scientists to the project team presenting their results, and assisting the PI in interpreting the data and relating them to health outcomes obtained during the study. By providing exposure assessment expertise to investigators as part of an integrated core, rather than via independent campus laboratories, we will be able to provide a much more robust, appropriate, and custom tailored exposure assessment through our synergies, interactions and collaborations. Moreover, the Exposure Core will coordinate closely with the Integrative Health Sciences Facility Core so as to optimize the overall design of the study with respect to both the exposure and biomarker or disease assessments and to thereby ensure sound science at all levels.